The present invention relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides an uncollapsed expandable wellbore junction.
It is known in the art to fabricate a wellbore junction, or another type of pressure vessel, at the surface and then collapse the junction so that it can be conveyed through a wellbore. When appropriately positioned in the wellbore, the junction is then expanded back to its originally fabricated configuration.
However, significant problems have been experienced with this method of expanding wellbore junctions. For example, the collapsing operation tends to work harden the material of which the junction is constructed, which makes the material less likely to exactly resume its expanded configuration in the well, and which makes the material more susceptible to corrosion and cracking in the wellbore environment. Critical areas of the junction, such as welds and tight radii areas, are subjected to very high stresses in the collapsing operation. Specialized and complex tooling, such as a built-for-purpose press, crushing mandrels and dies are needed for the collapsing operation.
Therefore, it may be seen that improved systems and methods are needed for fabricating and expanding wellbore junctions. These systems and methods would find application in creating other types of expandable pressure vessels, as well.